SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8aedc0c49048104a3bde6abfd9677a6522e2efd1fb3987688d86d7dd384d8417' 
  AND token = 'SKcnYzr3LhCR0mIYT03ac81fxurn+KAypZt87krVYX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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