SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2edd28ef633e68456ee5a27718397939751a28a8f93b98e1c541cb165ef61588' 
  AND token = 'flp47yxa7WtYZYPh8oYjXtAzjAezkjJwJMJ9+CB0yRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}