SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '39364e95eb9fa5814727742c89612b1538739c72edc0a6c6d87a286970a0fbc8' 
  AND token = 'Kfo+OTKKme1sp/57yysKtsZNcCOe6tGgIO4bA/5KVrA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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