SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8962ceaacc967b0d5f7d13aa8914671056b3549321c69a7fdd9404912c7d445' 
  AND token = '/jQbDN71zBlP9PVfmHyMeJquOBnGL4RYxyrVBZPnh9c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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