SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '8281bee7156ecaf6db6ec6ef1402c446606fdb60c5ff08626c13a8f95e16693b' 
  AND token = 'TqaMUcq42SV2rlWlJ0OakoFFNd0cYdpZrEXpkSgwJm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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