SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f979f91de7bbf201db99bdfcf48182a9457e29164f7f797242d7e9c3976f9b1f' 
  AND token = 'tFSCIDYVGytIdHO4qMFnwhPgVbunBzShBatjn05EzWk=' 
  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"
    }
  }
}