SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bd3764dc3097f7ef7c673434f69a31e15ebb9a572e0a3b2bacae0fc48080fd5b' 
  AND token = 'OxEy+AUegUUrnDO7+XL7PmWWjyz1WuFBXkEWwKYN38Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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