SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4a3b83903e88c9924fad4a5a374b6cf59189371fac08871034b15b899679f11c' 
  AND token = 'AcxiPCLO3UEz86+UKRJVLINVxWQhDqofyjgLlwhHcJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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