SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f384d7ded4ac4a37372f2b6a8da1fb153eb5538253dd41fbf19198592466f69' 
  AND token = 'DPJ/MTYQc+a1vcj8oaZ91fSp43UCyHGBAVNVbQbiQ9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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