SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b557ade196f5f58b2e72f4e342710de056c35f265aae938f573e8400d84931da' 
  AND token = 'Z6b3k7Ku/F9+F03GfmQyt7KC2NLG8+VOcJDYaWKNmu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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