SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b12834e81a741f2971f1c01f180b66eb15a7d029ee94b15c762ad6381ec01987' 
  AND token = 'ZTmU9MpJgMrPyvJbtYdK2/VRKXZuLkc6plYGtLbwy8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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