SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '869afb25b125091bd775cedc6f757800b2e58cf9121c790596669655d77eb96f' 
  AND token = 'MEjLImDQfl6X0DnudtfvXE0l/9iTQ5jNTiJEUxtMgbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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