SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '58e4ee848fd7009f91df6820518c0ab73113a33ab23dfdda6114ac9ba2fd8d79' 
  AND token = 'qB4EUS5MfewuMTIFN2+BJgjOTYJWH/VO2NLIejimPVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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