SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b83db3a29db808d14fe10275b6cc0b452336515f464b11fde3e94ce5ed93918' 
  AND token = 'hfh1a9V545XZkWy+jrwL+kqBvYglkMXE/YQrFdbfDi8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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