SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7916d82e696561e85ff420da3a16fb0ada078c6a54da62611c8d1af73fbff701' 
  AND token = 'hqudywS1uALu7FCjO6VWuzd9Q9afTpkLcqhtqRihgbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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