SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4408912db8b3cdaa74185ce26a886c6aeb9711702be18e7dbb407f2e157b79a1' 
  AND token = 'klmOru997ecIrqNx8hJtFMx4bLr3kygfyL8DkFLrOR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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