SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ee40cd16f76eb9577234faa432025e555cd5dacebd26a52174e9901fa66b4c8' 
  AND token = 'rpSz7nXGxtluXbJ27wIVNyxlz0tUEkrle7wTR3Dt2yI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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