SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a06f511dc8d7ff2f8575d3ceea81bed42aca7f8e7d55107cd76c7eebfbb085cf' 
  AND token = 'kuSgH7gx+WV5ZfsekhlVvgNTFs1XDkAi49FuY53kPpE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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