SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8db4830e4eb465534434f07fb59c2a6fd699ab60ad707b32d7432e6ff687b39b' 
  AND token = 'iPWSTqQWUTjaT4JWG8zJWEIXsjtm0rnzkuzjyZ11Ggc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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