SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '241483fe15317bf44888e961d6fa4ecded9fa2bdce8952661941a43a6d699f97' 
  AND token = 'c5Esa8GcDCR4ApYH/H7JFlJLp96etalzBfUiyNMbHdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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