SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6eabc98afc2a7f4c872645abcd906f0c916aae098f641c35a556e1ab1d719cb2' 
  AND token = 'wI+pecuGULTYEUoO3uxMywd/KQ7ivqxzyOUwBDKrlDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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