SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '23f5bebbf5f9e783c9bc279d5d5066380e1bf03e383264b16b8cb0a793b137fa' 
  AND token = 'MJClkr/XTjw/sWkdYOyrpEQdsDKgdJ0B9OeajNX+nCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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