SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '554e39a3f294bdad298f745b51ff02d1c7f41961169e8349363f97adebb11132' 
  AND token = 'CIlxhhA8EMJvGFp3+si8y83RUxhCCVEUdSqmhDekcjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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