SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6da8a477364bb6b33b1696e6dc88de3068a1d49f301fbff916ce7f55c383d9ff' 
  AND token = 'ZFNYyb73036JhZ5I2hGg9Yg+dQYl9xIDN3Pl6rCkaBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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