SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd7fe3f1acc8fa7053f8205c206ba6915ef5067dbbbf6c9115959d2f072535ea' 
  AND token = 'QZbZCL7sFpSC9/3KEPvfMawQIfq1+jxBT7qRWwU7xq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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