SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0f64965036727597a49252e01a0653c9ca5b541b0f76ef43c4c69bbbb716ea6' 
  AND token = '7WD/Znw79Uh+WTYleeiTgwJkIYyGu1gjaSc8o5soUAU=' 
  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"
    }
  }
}