SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93a5f1e48d1e83d4d653ee1632e38e00d82a73a1e79750e4aca812461449c4d1' 
  AND token = 'taPFVWJgqmwRh+oo9Bmlpi5HmiUW2TfHQV0YckzhcjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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