SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0d2bb1511df5da1bad5ade4f49c1a443cfef0b7bc84bc3a35dab9a7a876ddcf' 
  AND token = 'YtxXtbllSrDN8hNr0ez+2T4X2imdJ5BXsOr60rzWmKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}