SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'bbee3b7f8b01f6984a35b3ef5373d91edf8b7b97add4cde848ffbe9b663c067a' 
  AND token = 'XWykgbeJWUjAnprQsFo0ZZWCti31fLDN4msym4tyUwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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