SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '896f9d3205d56e2d48a16abe06bba0a034f954baed34731cc4d818e63d9e6558' 
  AND token = 'gQZD51PQno7D7cGvfdoSrdsZ2JpZGlbnQyU/3YDnaU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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