SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f945c497a87704ca80d8907c1e9bc9872cca97a8b31840808a1d8e2e3b4be9e' 
  AND token = 'R+wEFfy8I/NWgDrqQyh9NwliL0/gfNgTYegYohKbUd8=' 
  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"
    }
  }
}