SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fe5da01a5e7f6a297e168266cbef5f27038f2863acccf7610c00a0b8642fc0cf' 
  AND token = 'ARZ1BbZfHY8aGY/sTXAYfJh6BF/RiBsirBixdjPKgyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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