SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40ee47912a0eb309053c3256a8f05b0808d82aacbb1a257a102e2bb3d205ddcf' 
  AND token = 'IydFV0lODqOjElHgde4thrZXfYJXJ7EbMH3SpHgSdSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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