SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0b0a04817891c32f360bc4e47e98c0a9dae64e38ed8c675643a548594413d6c2' 
  AND token = '5+T8GCwkohfrYjdQZz9FkZ29EfYOw2Cn/589HH/nhq8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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