SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9849f79afc0ec1686e860fa13fafbaaacad42d87938c0e9dd1de605072d482d7' 
  AND token = 'BWD3ot4y2JEBlkdrR0bqxMCOteOyun4xJ0qDDxeQarE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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