SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '276575b4124ce9da8f2ee3cd1806e4039a5d5dd50791a021fdc9eeea9b07b44f' 
  AND token = 'K+m5hR5m5iD6Op/tR/SUXSf5K3SThRI58nGjcr/hfFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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