SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff8bb817c74071d9ba5122cec94cd7819d9448d908d07420d131d9e8263e3723' 
  AND token = '9EHnKcCvn6iZAsmj1wtUHWWKLp0K7fNCpxXDPvkhz54=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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