SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2843051be9c3b6572d6064a69cf33584013a15116c3207868cb3e00e15e742de' 
  AND token = 'v6HUIwV1yzL8IBuFEOkh6CsxdYHRu2AD2HMKPaw4XZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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