SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a81b5053e93acc0a6d2a5fac925bc0db9db4c0979a059129042441d741f13baa' 
  AND token = '3EODRuQyLvAoEqCWQIzroA6S4kG7nOX2AZHFqC73u6o=' 
  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"
    }
  }
}