SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15d5528abfe9cd5eba6c7bc65b2d53f64473ce061692bed917eb7467b8ac5e94' 
  AND token = '+GWBufYC77wcq1qBhrxk3kTcHau/qVCmaDKhZRYQ55c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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