SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b96a658b7553b3864fba00d3ae8d7d38436a41a9b1e4c529b359c7755a98b1d' 
  AND token = 'Qxz5GJwXvKvdaICOLG4zxeYBy6Iv4R+0PHofMjzU+iA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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