SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '472adbcaed77da28590903c78d2e5544022ca97459190f62bb07d4922c6cddc4' 
  AND token = 'wO6HerQx7elI8MsgI83rwEArfwgfvU/3tw8qmul/CD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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