SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08defd978f8e58f958bbd761b9e81a996e32318e50faf54ea210a8a8db2b6387' 
  AND token = 'wrgcHJTQKaQgJK4AoOKDVCMUcEPD9X7hTKNDWu/40tU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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