SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5a5c4725d735324ea96580b75ed69b1af74df0e49d94988a24119814dd5ffc5' 
  AND token = 'UJn0Dy0UxFwIOPOyK3jjuwPgKlNuNHrWufZGKMSaqjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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