SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5463ee0abab139f029fb7fb3a653adb83779252b3e865c0ca2007bc9fa07cb3' 
  AND token = 'kx/uKD53OjYx1GVHPaY+/pKDXDzuxdMf65/HRoZE7cQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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