SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '315ad01da2185ab28656cb225f6b5ea3775fa3e6d74bf879ff81a645719e1c42' 
  AND token = 'LOnq7ZNZ/vl+cC65q25ykfkNLP2MbA4RetXRidRd29s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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