SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65a45323e82d23a69427bc51ec2f8c9e1eab87eaee9a567132d6a4b537e6d689' 
  AND token = '5B311MimpMvCX48XeUWrU/qJoTnKaQKaLyfpFYikLWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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