SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daff54ca1f9692dca008644c513a0f2ac9232b88f1467f23c38da9257680f24a' 
  AND token = '24umEJG7svloDF5Vsgr9dxftMih70oh9QUKvCi4IGZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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