SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e718ddac00762d491f3eaa18188f36f2ce1be39edf3d61766bb1cf1607b9db8d' 
  AND token = 'yT6wBuqqWNSph2TcoR8RwdQZ02wZ+VAyeLa4w6WraN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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