SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '08a472bb4b59030611a8bd357735a6b577e07f73db75406ee834c033a3ed6cb9' 
  AND token = '7Ac2KdIU4OCAJSI48bvRdfOyQpe4AnsaLRxkgNOe4Xk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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