SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e93c49a06936c66b1e052468f66f75bfd47833ff37d81acbe92eab71e87f08a' 
  AND token = 'nLssvhTSm731TfzbIrq/mprZ+hgjEK9VaEaVyYAtG2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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