SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab8196aec31796598d731ea6024872fc4eff7cf96c5ba9f8e65a870a4a5901a3' 
  AND token = 'u+wdN3Jy7mo60sjJTs0miualXHY5xdthF8vYn6D9yAI=' 
  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"
    }
  }
}