SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a3db2a1634dc503b265363d3b9a9c055c4699b01a2577ff75394e6dadd14ae0' 
  AND token = 'xJaNJqSXo/sUH/yPO5+mTGhBAnz68zHtjM8Xw6+Oh5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}