SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '309f766bc9f2fcfc5d3fd95185153f6dce96afe5ed6523db766a2d21fdf36e2d' 
  AND token = 'xpr7XcNg6nZZulI2GII5qE4orkzMgsq7ObOKASUkgEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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