SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '19e7edfbc08d95cd6494711fc5d09e06817a35864f3bcbf3cee8ccb0d3381102' 
  AND token = '6ZA/2h3G2ZEg8zS9Qsq396zWXisB7IkvXwzX+D7ULsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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