SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f30b8430c31c0549517922f32f5d20f8931f0148a48b33acae216c5c132feaa4' 
  AND token = 'DOl3vxEbT89lPA3BMLMQelE0RGA/PZQBwgHKROR6UVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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