SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9aef51cc40444864592cb1abfc8bbf2f4d0fdd748e6b021388a254d641e0fc13' 
  AND token = 'BW7YnSfKsgACUTLbQPDAQ8/4uhg/gGQZ5A6g8UGZlMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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