SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8fcc665111256d5589bcb4a4f38ce104ca1765862e072d77f54ae4b4051c378' 
  AND token = 'aj5qRvZxBqUfy8y6ON1CUoVPZtI7ZGI7epqiWWxySuM=' 
  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"
    }
  }
}