SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '632c4c31f01302e0021f7590208b9a4da8fb863da0f88852bf01cb470720fbc1' 
  AND token = 'sZDUGVOnG4aqwqtIw5HTSO/zOjEOrPgLX0cu48MtWUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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