SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fd8e958c5ef76743093eb22f647246596565b7452b051309a65c9633ef8c6ed' 
  AND token = 'RtaasXr8n7z7yWfluqRZopcwitM58o3hwuQXzEu81eg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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