SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72f7029cbd8b8ee61b40103b0bd727b764f0ebf4bcbd4449ac80ad1aee5f6557' 
  AND token = '97UGLhTcM5KqpVddQ+w013vJ5jqZsi8YlghPB15g5R4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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