SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88a7d71f9e07b6ba9580fb5fcf1e5459d048325cf1b3c4963e668f87195bfd8f' 
  AND token = 'DwZjUitlEg+mXN0xGMmC+ss6ILhCFvRW4d6aXMSJMPI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}