SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30cbff268af12bbd06416989c625b002768b7b4988b59917d7014ace7a1b31be' 
  AND token = 'eTE5SswdMJmnYoP5pTuOn9hko5pVDr+JUx+kGGyWpKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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