SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53e63e318ccca325c62f160507c49269d60fc654ba3650b310a3a59ed61fb5f9' 
  AND token = 'omgX9j+1mtCb3FUPjudO4NLK3zch88fI4Ay+oOwdcHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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