SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f7b5462bd585acb45bdfc5012f1f141428ef9b10019ba7da2c5388861e26ca2' 
  AND token = 'bp3MikLu0Ir6bsni7l3Vqw0N2Djti19pA2XfV9dJysc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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