SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4ab8042b74440b2a59d2c6e11eb35a44cfb52eee81469cccff9b8bf9ecc75779' 
  AND token = 'KhG/NISTJYGmN3IMmw4UjD0hKNyFlCuOLD9WZDPLwiY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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