SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bf6bf95565912526cb5a3058ab6655f17390d2a4929f024fadc37154b378fe6' 
  AND token = 'Sg/HHJY4f0+pGfT54eCLe5fkG9L3wVctM4ewkPyYe0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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