SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7963c6d444e8c273441c579fc8992225c4e2a106b77598231f5a202d12e4f058' 
  AND token = 'UtDDDnW+YiEnBuB0wQ4C2sVKi3YYSIK0vrJGRbZ/0x4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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