SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'decb0a1f673ab24a2f56ebea3d42224670d44972392ca2903ca8da5fc49dfeda' 
  AND token = 'SbXAsqF/nqdndsdLhyGvhW2g7ZjDVvn2aHYTx98EKIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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