SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf927242b836f8590a140366907e566c0cf2d8eac9a5f4673a41f50e1811c60d' 
  AND token = 'XWhJoCHTCk2dT4s5jXxGhZ0Unq+4p6VuKmXu5j/Oq20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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