SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd661954656d51d4aa1a788cfd474f3949b0c3c162d1ffc15dfa0a25d4b77310' 
  AND token = 'fo7jQGFtQEQKSvXnD+J6ceIdL4zg/SNgExKRruTA0S8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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