SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86d7f3d8a7a83f9bf09faffd12f1426fd564b73d32575a6ca45f3593a0ab10d4' 
  AND token = 'FtuLF6NlnNQIFlmWxxKTWBLcGvuJm90N8BeOItkyhhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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