SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a6b911e4d11c6878fcd72506583c0f98e4fb4a06eff450b968abe31a5275ab57' 
  AND token = 'LGBaRnYHu0XmJ56yJ2/fUzw+PVDGHx7tuY7EH44lAxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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