SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d3b8d7202bcf4f393918ebf77b0fdbcea8a7915f58d055f2bf9cd7342db9309' 
  AND token = 'Bl7Q5HVuKP652r9ucSOVKDMEj3kbxq6wIH10YP0/IqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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