SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b29ce4aae0e4a562ff8c187d3482bed06ae0e1e9dba76db99039b7dee2cb580' 
  AND token = 'TK3lJ+RfJf7I4V3qDgszBKYG62QLG7+47s4OrVUsAgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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