SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e5ce82ba22d16528c9a7cea1897ddc33de6995655d9f21d05adeee3acb09398' 
  AND token = 'vfbpiwLLtn/HX71eJaWASfrnDhWPistqQeyR2hQdYIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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