SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4100903da0d64b929d2d6952a3ed169d41dd3004f8cbd05820fcc1dbed40797b' 
  AND token = 'd8gc3ONm5jZMJMPr8tY0t4yGyeOEoawmhHTJ6TplcxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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