SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb9a9fb95f691555d31e8346a870de3d92195a7818facc355a379aa968d0e915' 
  AND token = 'lCF4vFogVIdCUaudovT1womadNuzZD9QwGxdCKP+Npw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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