SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5837e41bcc1d1594007c48e4e92e7762579a59e41a045671a56af1f8a77f4966' 
  AND token = 'AiCzr05sQOAsIMSYD02HSZsyW9MOzTbwn23dzezHacs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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