SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30fd7125f5d0ab80c75fea1b7d8bce549452bfdfdb148103889ed909daac489e' 
  AND token = 'Ofc53OGn77KkoJf4lMVsSntTUuHFsxEwnwgEG5vljn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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