SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '0ddc29d354dd34e1290049d937c9b695c2ab389816268f6f0b5d72d39c01046c' 
  AND token = 'e/TMl+8XlFRE9K8CPfkqPKYB/UZC1FMMQSpMqixZvrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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