SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79c1aaf450cff135778ca0893dba62cd61cb85c60d402b3e96f1769155248772' 
  AND token = 'twWR0QhhLDZQPB1g5qs2LPvw+5/QwzBSj7XyHd7yPKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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