SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0f6fb7bcab97e42a901f1c19fdc661933c68b90fcb477aa094ef406253b6358' 
  AND token = 'EjljmOKVrOPxdTmSNo3i29vS/iPfzzWmNbS6FkL0zu4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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