SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a85ca2a44758f2d58eea5c348d6b7088d300bd58a135bd879558b6424273604f' 
  AND token = 'bST/KZqv1ZfKQ/0XO5zbVeWYcWMaatxcxzDL54lYyko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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