SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5a5911d87d90ead8612d5eb037cc12dc2f5e953fdaee5a4ce6a38c14dac3125d' 
  AND token = 'MY5gaeHqLnLM96xFnzjdCEpAh4qz50HHd2dy/yI2w5M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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