SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6734888afe30842d91e11873237a6b539975d628a78edcc591ae84d821487c53' 
  AND token = 'Yww7MGwaA3Xp7xhVWBnBz+6o1+F367WAxNiVh/G8qXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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