SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54a380702a56eb53a97acb298d9382edaa733f128e9a5883fd8b4a1442a97772' 
  AND token = 'H1m5IGvF+EzX6D3M4KlhN8qiE+UOjY1DRJPhtPbLt2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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