SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da28939c6f4d777cac261b4c686d1f900765cf38c125cecb74c88000ff04cd81' 
  AND token = 'oGOu4uqMbUMVAkJPbLbZ0QFF8uYrjPHQpntB74iP4Mw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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