SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '344cd2fd5150dcfaffadecfa183c8368e9249069865e450f4ad91b7f608e7e77' 
  AND token = 'BYVRzmRRJVj2NZ2CaEXvLOqCcR9H6yNWW+5zIe8sr/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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