SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb269f277bf405bd004024f35447cada57a22f29b5acc44ef9de74dc4447fd6a' 
  AND token = 'bqbQTCGvScUePCsNbKNNjxVKzyY5NtSlxOrit489vrY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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