SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a88560e38fa7272044519817f0f153fd547cee694cedb896032a20466dd0088' 
  AND token = 'vrh3Hmn1BRFVHq+Pc1RQzW+B9Gr2EYUXUlRndD2LnTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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