SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '54d9f8fba70509901a2f876d3aa3351df8dffb973945bd9b64c2aee6f428b27a' 
  AND token = 'gx2f10fc8sF9g1i4WC7xcw8dCLULk2yxpDdSFExKq8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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