SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d798fa6cfc62ab749edc8f6cf4b4e1b41b0f253c78acdcb267b9368417e1299' 
  AND token = 'nrtdu9rw5AuBe6AP4NddkISMMedjEucS/+fNjYSK73Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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