SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e63aefcb2e2ea0588a0b2d6a2b9a6379c3451f450c225f893f3a3a203f618548' 
  AND token = 'U8CmrCY4uIKAUTOLOFP9peo2R7OtrQhlo3Ivy5US1pg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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