Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3e9df9a4b0ebb0a0755ab6b553936e82d664d64487336eeed1e44cc7c9b15d5' 
  AND token = 'EymMUr9VfwGsYFkaaMAUhebhgA4fZgg3b2sUh60fmqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}