SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cd9b3eadafdb2143698f6d016052145723dae075ef6d61b38926f6f61ffdf352' 
  AND token = 'AUR6P9Axx7hOqjUrrdZGz1Uo0RquRaJ22hB6gcEKKqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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