SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '1e4e7ca54f13d1b521234bfdb15352f36e9585430ca01c836a3fbf5d160f6d5b' 
  AND token = 'qJqoV0aqPVjQrC83ILjNfTP2CpdOqwvGYi/FSXdD2HQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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