SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '77f1e15872ba7f03ad65c39601bc7e03f720fad1892e3e38f1c39526cf0f6c2a' 
  AND token = 'TUUsMrVPpYBKKxiu/n4O3ShX/5DuH5cX3Aa0/J3e9yI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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