SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba0b7ea66355e1e504149419a2adbb7abe026db2fafc128e92a99ed837268c45' 
  AND token = '81r4DADuzwvPCJLlEeekCcEIxjsuBaG/AxFTjtBXh4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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