SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '027fe5172d765b1b0143832d9847c551ec2fd1f92a184cb64d48e80eeb9d1ffd' 
  AND token = 'TMEgBgHMAqIw+z+Kvsm39vusKX6N63wPhIGsuU1smJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}