SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '926132efec77306c5cc99769f09c600048e874d4412ae1d49ea3f88736a40dfa' 
  AND token = '/aooHsegUIBSbMwiWl820caJ6pOJPQqzJRHfcreVyPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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