SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '871baae69d4dde29163ab5e95130a9cea1932d40c1189db53858b5559229c7e7' 
  AND token = 'WBRO43NYHRKON1uv/EI+g+BxR0cfhrGPjlhukNNYuAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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