SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '9b72571161299a945d292389f0a5a817d695697140d5e087fe4edccbfeb8b782' 
  AND token = 'fD5sZVAqQvl4XvSAAWvHmCS01vNvNNiSQ59E//8s8tY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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