SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b09c014b63df5940e5fa9bf51a0f6271a6120038c2a61aa66a52d09441f83fa' 
  AND token = 'sZecXlUuTmNinMpx1GIgOkr/nE16UfJAODB5KDpAGAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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