SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '560e43243055f22f304a3bd37585321db1fe825c8bbfd7946ae4d7bce1ca7048' 
  AND token = 'FIoMDs9Z2z0mqnWp9j6IgkgKLx3xZ3neyRSerc6dB9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}