SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '595231167c79a4f46c2e70ee8ce74d2b98a7dee0cb1e8d569db1d5c2836f7308' 
  AND token = 'kKrnqmBDITk+AtD8K3SB3+MYpDhSmFO7jB0bggmjEwc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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