SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11af8e40873cca3291db0eafaed7924345ea70884806484baf2a4da25a368400' 
  AND token = '8T4//dgZOPSKxA5wuz4Ii1lKaPtDn0udYw2Vv1DLPdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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