SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '781f7949966dcb359df692f1c61097d1351991561d9c0e79bc32e1eaf229d314' 
  AND token = '7sIUVfwZuNY0g9MV3/fNGrYFLfybdKobVUjGXsGMc0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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