SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de574af630a272f8925a7af627f4e94b4cb435021a6541287fd7312eb29e0e29' 
  AND token = '3fwsTTrGnz6kv2TT+HcS3vDIHPDPUMF7oaALkeGBgYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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