SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ee490864bfcaeda9bd26a39d98fe0f27e2118928c2e8d49a494b55711409c06' 
  AND token = 'mw306uNKGJqfzOGujDqzXoDaC7BjJZGE8HC3vgcxMbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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