SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90567bb656c63b85a64f00aa6ba95b62ad56803d374df23b29115ee4def212b2' 
  AND token = '+XUMUzxZhal3K+YUygMSwoOOxX0BYzGiJky0CYs+Um8=' 
  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"
    }
  }
}