SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58fb15a0f9e27763e6b601346e46e561c73bbe9b2f87e6d53b400a5eeefbb612' 
  AND token = 'HZSOdQLBE4Vnwfx+ocvXpW0M55NH95ergsl6QI8FRVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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